Non-Perturbative Treatment of Highly Correlated Systems: "LDA+U" Approach
Abstract
A generalization of the Local Density Approximation (LDA) method for systems with strong Coulomb correlation is described which gives a correct description of the Mott insulators. The LDA+U method takes into account orbital dependence of the Coulomb and exchange interactions which is absent in LDA. The scheme can be regarded as a "first-principles" method because there are no adjustable parameters. When applied to the transition metal and rare-earth metal compounds, the LDA+U method gives a qualitative improvement compared with the LDA not only for excited-state properties such a energy gaps but also for ground-state properties such as magnetic moments and interatomic exchange parameters. The basis orbital-independent rotationally-invariant LDA+U potential gives a correct orbital polarisation and a corresponding Jahn-Teller distortion as well as polaron formation.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1997
- Bibcode:
- 1997APS..MAR..N103A